Brake



Oct. 25, 1938. c. SERAGG ET AL BRAKE Original Filed June 27. 133-3 2 Sheets-Sheet l To Sucnon INVEN7'OR5 Ca/eb J. Bragg 1v y Uicfor H2 K/ieamfb ATTORNEY.

To Cvunon.

To Sucnon Oct. 25, 193-8. c. s. BRAGG ET m.

BRAKE Original Filed June 27. 1933 2 Sheets-Sheet 2 lt-Ill 7 Wi /t iiul. Ill v\\\ 'Peteilteil 1938 r BRAKE me-m 1 Divide! In! tlill a, 1m, Serial No.10?

- an $1.1m. Serial No.

ham 6, December -21 cum. (ol'. 188-188) This application is edivieion oi our application, Serial 80.464116, which huiomed as Patent No. 1,945,515. The aubiect miter ci cert'ein oi-.thec1aims herein'm disclosed but not claimed in our prim-Patent 1,928,185 issued upon oppiicotion Serial No. 265,091, illed'llemch 2'1, 1928, which application was with the said parent application 464,176 but not with purposes oi mostretiol'i, and the aid invention 1 a fully disclosed in the iollowinc description and 1 Our invention rel atea to brake systems for autcmotive vehicles in which o power actuator opented by differentials oi fluid 18 em- 9 7 oper ting l'the brake m pnditisespeciailylpplieabletovacuumbrake for automotive vehicles in which the differential: oi fluid ue obtained W iusingatmocphericpressure ondcuctionorpartie! vacuum conveniently obtained by a conneco1 internaicomusual lpcrtiallycioeedpoei u'theloweriiuid Inearqingourinveniimintoeiiechweemployacontroiiingvalveoincvelmd Thevalvemechanism whicmdurinc thepowerstrokeoitheactu ereaubiectedtodiiterentialsciiihidnreswlth those. in the ectuator uarewtlonmiorceezertedinadirectoreoistthemovemmtpimoperctoropato continue the of the tonor'holdthemovoblepartorperis there onmtermediateoithepowe 'ltroke when: operable pert havinz 5 comwith the brake and with the ectuatcr, and in (her case a. follow-up" ctthe valve mechanism-may be cecuredto edout intheeiaiihs,

Merrinl'tothe momm diowih zswhicn illustrate several embodiment: of our invention aelecteiibyustom-pummelo tillustmtion.v

l 'imlisadiog -emmaticviewoiohydnuiie brake system for automotive vehicles.

endtheeusinecyiinden,

- mtioninwhichthevelvem our invention end including o pressure-balanced power octuetor and controlling valve mechanism mentboci'd.

.l'isJiledetaiiviewdpertldtheoppenms Mien. 1.1m colizi modification 'l'izJl h i m atli -tfi'er modieehenimismountbrake shoes Ii, hinged together at It, and having their upper ends engaging the usual expanding member (not shown) which is operated by the brake applying lever ll, the shoes being provided with the usual retracting springs II. In this instance the levels I4 0! the several brake mechanisms are connected with the pistons ll. of hydraulic brake applying cylinders It connected by suitable piping II with a main hydraulic or pressure cylinder ll having a pressure piston 19 connected by the rod or link It; in this instance with a power applying lever ll pivotally mounted at 82 on the usual brake pedal lever 88 provided with the retracting spring I. The lower end of the power applying lever Ii is connected with a movable member of a power actuator indicated as a whole at P. In this instance the lever Ii is shown pivotally connected to and supporting a cylinder l of a power actuator of the pressurebalanced type having a piston 3, the piston rod 5 of which is pivotally connected with a fixed portion of the chassis. The cylinder I is closed at one end and open to the atmosphere at the other, so that the rear face of the piston is exposed at all times to atmospheric pressure, and as hereinafter explained, the closed end oi'the cylinder l is connected by the valve mechanism. when in released position, with the atmosphere so that the forward face of the piston is also exposed to atmospheric pressure. The piston is, therefore. submerged in air or pressure-balanced when in released position. The link rod It is provided with a slot II surrounding the pedal lever and providing a slight amount of lost motion between it and said lever. The spring is normally holds the pedal lever in engagement with the rear end of said slot 83 when the parts are in released position and it will be obvious that when the pedal lever is depressed so as to take up the lost motion between it and the link rod 80, the physical power of the operator can be exerted on the pressure piston It and therethrough to the brake applying cylinders and pistons and the brake mechanisms connected with the latter.

The controlling valve mechanism for the actustar is represented as a whole at V and is shown in detail in section in Fig. 2. The valve casingpreferabiy comprises two members i and i. which are conveniently made circular in crosssectlon and have their marginal portions connected as by bolts or screws 'lsoas to clamp between them a flexible diaphragm valve I. The casing member 0 is provided with an annular seat member ii adapted to be engaged bythe central portion of the diaphragm and communicating with a tubular connection ll. An annular passage i3 surrounds the annular seat meal-1 ber Ii and is connected with a second tubular connection Ii. which conveniently has its axis disposed at an angle to its connection it to facilitate the installation of the valve mechanism. The face of the diaphragm I opposite that which en the annular seat II is provided with an inlet valve chamber it having a centrally located internal seat indicated itilm This chamber It can be conveniently formed-by a stamping II or sheet metal provided with an annular flange portion II for engaging the diaphragm and having a central aperture Ila This stamping may be conveniently secured to the diaphragm by rivets through the flangepottion II" and through the diaphragm and a ring II on the opposite side thereof as indicated in Hg. 2, and in this instance the seat portion i1 is conveniently formed by the walls of the stamping adjacent to the central aperture H". The diaphragm 8 is provided with a plurality of apertures l9 exterior to the seat engaging portion 8 thereof and connecting the chamber it with the chamber it in the casing memher 6. Within the chamber it is located a valve ill having a valve stem 20 extending through the aperture ll without fully closing the same and having a guiding engagement with a sleeve 8 on the casing member 6'. The casing member 6 is also provided with apertures 2| so that the outer face of the diaphragm 8 and of the walls of the stamping I! connected therewith are at all times subjected to atmospheric pressure, whether the valve it is seated or not.

It is to be understood that this form of valve mechanism is capable of a very wide range, of use. as will be hereinafter more particularly pointed out. The connections l4 and it may be connected respectively, the one with a source of suction, i. e. the manifold, and the other with a power actuator between the piston and the closed end of the cylinder thereof, and in the alternate positions of the valve mechanism, to-wit. with the diaphragm I seated and the valve ll unseated on the one hand and with the valve .III seated and the diaphragm unseated on the other hand, the cylinder can be alternately connected with suction and with atmosphere, while if the diaphragm I and valve iii are both seated simultaneously the cylinder will be disconnected from both suction and atmosphere.

In the installation shown in Fig. 1, the connection it is connected with suction, being in this instance directly connected with the intake manifold ii in any usual or preferred manner. The connection It is connected by a pipe 65 which may be in whole or in part a flexible hose with the closed end of the cylinder i. In such case, when the valve is in the released position as indicated in Fig. 2 with the diaphragm t seated and the ve it unseated, the cylinder i will be disconne ed from the manifold by the engagement of the portion 8 of the diaphragm with the annular seat member I I while the cylinder will be in communication with the atmosphere through the central aperture I! of the stamping II and ports is.

In the installation shown in Fig. 1, the valve mechanism is connected for operation with the pedal lever It by means of a Bowden wire It, the casing of which has one end rigidly 'secured to a bracket It in fixed relation to the valve casing, while the other end is rigidly connected with an extension 8! of the power applying lever Ii.

The parts being in released position as shown in Figs. 1 and 2 and assuming that the engine portion I of the diaphragm which will be elierted in a direction to hold the diaphragm firmly seated on the seat member ii. To effect an operation of the brake mechanism, the operator will depress the pedal lever 88, thereby exerting a pull on the Bowden wire II which will first seat the valve l0 shutting oi! communication between the actuator cylinder and atmosphere and will then unseat the diaphragm I from the seat member H and thus connect the actuator cylinder forward of the piston with the intake manifold. Air will be withdrawn from the closed end of the actuator cylinder, and as the piston is in this instance held from movement, the atmospheric pressure on the outer face of the closed end of the cylinder will cause the cylinder to move in the direction of the arrow, Fig. 1, carrying with it the lower end of the lever II and transmitting the power of the actuator. which may be multiplied by the lever B! as shown, to the piston 19 of the hydraulic pressure cylinder, and thus to the brake mechanism connected therewith. The brakes will be applied with increasing power as long as the forward movement of the pedal lever continues, and if the movement of the pedal lever is stopped at any point before power of the actuator is fully applied, the continuing movement of the actuator cylinder will cause a relative movement between the power applying lever and the pedal lever and will effect a movement of the casing 85 of the Bowden wire with respect to the wire 84 so as to partially release the valve stem 20 sufliclently to permit the diaphragm to seat on the seat member I I, thus closing 01! communication between the cylinder and the suction in the manifold and arresting the stroke of the power actuator and holding the brakes as applied. This effects a mechanical follow-up" and enables the brake mechanism to be applied proportionately to the extent of movement of the pedal lever. As soon as the pedal is depressed to produce a power stroke of the actuator, and during the entire power stroke thereof, it will be seen that the outer surface of the diaphragm and shell or stamping l'l will be exposed to atmosphere, while the inner surface of the diaphragm will be exposed to suction. There will, therefore, be a differential of fluid pressures exerted on the valve parts corresponding with that in the actuator and exerted in a direction to seat the diaphragm. This differential of fluid pressures will be transmitted through the valve stem 20 and the Bowden wire to the pedal lever in a direction to resist the forward movement of the pedal lever, and will be felt by the operator on the sole oi his foot, so as to enable him to determine the extent to which the power of the actuator is applying the force to the brake mechanisms. The degree of re'ac tionary force thus provided will depend upon the diameter of the diaphragm 8 which is exposed to differentials of fluid pressures during the power stroke of the actuator. In some instances where it is not desired to unduly increase the diameter of the diaphragm and therefore of the valve casing, and additional reactive force on the pedal is required or desired, a certain amount of the power of the actuator may be diverted for this purpose. This may be conveniently effected by pivoting the power applying lever 8| at a point on the pedal lever eccentrically to the pivotal axis of the pedal lever and in such relation thereto that, during the power stroke of the actuator to apply the brakes, a portion of the power of the actuator will be applied to the pedal lever through said pivotal connection between the levers 8| and 88, to-wit, at the point 82 to exert a mechanical reaction on the pedal tor in addition to the reactionary force caused by the diflerential of fluid pressures on the valve part.

No claims herein are intended to read on the specific structure shown in Sorenson Patent No. 1,953,057.

Where the dlflerential of fluid pressures on the valve is suflicient to supply the desired amount of reactionary force and no material reaction from the power actuator is desired, the power applying lever may be connected with the pedal lever in substantial alignment with the pivotal axis of the pedal lever, so that any reaction from the power applying lever will be taken up directly by the pivotal connection of the pedal lever, as shown in Fig. 6 for example, in which the parts corresponding to those illustrated in Fig. 1 are given the same reference characters with the addition of 100 to avoid repetition.

When the brakes have been applied by the full power of the actuator, a. further depression of the pedal lever, which will take up the lost motion between it and the forward end of the slot 83 (Fig. 1) will enable the operator to add physical force to the brakes in addition to the force exerted by the actuator, and in like manner will permit the brakes to be applied by physical force alone in case the engine is not running, or in case the power should fail for any reason.

The adjustment of the valve by means of the Bowden wire must be such that the stamping I1 just clears the casing 6', when the depression of the pedal causes it to engage the end of the slot 83.

In Fig. 3, in which the parts corresponding with those illustrated in Fig. 2 are given the same reference numerals with the addition of 200, we have illustrated a modified form of the valve in which the diaphragm 20B is provided with a central aperture 2" and carries on its rear face a shell or stamping 2|! forming within it the air inlet valve chamber provided with an annular valve seat 21'! to engage an annular conical seat 2!! formed in this instance in the casing member 206, the shell or stamping being provided with lateral apertures 2|9 communicating with the chamber 2l3 which in turn communicates with the connection 2l5 ordinarily connected with a closed end of the pressure balanced actuator cylinder, while the connection 2 leading to the valve seat 2|! is connected with suction. Within the shell or stamping 2|! is a disc valve 2!!! carried by the valve stem 22!) and adapted to seat on the inner face of the diaphragm and close the aperture 2H In attaching the shell or stamping 2|! to the diaphragm, it is'conveniently riveted therethrough and through a ring 2I8 which in this instance is on the front face of the diaphragm and extends to the edges of the aperture 2"", so as to form a support for the portions of the diaphragm sur rounding this opening when the latter are en gaged by the disc valve. The operation of this form of valve mechanism will be exactly the same as that previously described with reference to the form shown in Fig. 2.

Either of these valve mechanism can also be used for controlling a power actuator of the vacuum balanced type, an example of which actuator is shown in Fig. 8. In this type of actuator the cylinder is closed at both ends, a portion of the cylinder forward of the piston is at all times connected with the intake manifold, and the portion of the cylinder in rear of the actuator is normally connected withthe suction source through the valve mechanism, which admits air to the cylinder in rear of the piston to produce a power stroke and withdraw the admitted air to release the piston and permit the brakes connected therewith to be released.

We desire to have it understood that the valve mechanism can be operated independently of the pedal lever, if this is found desirable. For example, in Fig. 5, in which the parts shown in Fig l are given the same reference numerals with the addition of 300, we have shown an installation similar to that illustrated in Fig. 1, except that the Bowden wire 384 extends to a button 384, on the dash or instrument board, indicated at I, the casing 385 for the Bowden wire having one end secured to the bracket 388 and the other end secured to the instrument board I. In this case the brakes can be applied by power by simply pulling out the button 384' and Bowden wire 384 to the desired extent, and during the power stroke the gradual increasing differential of fluid pressures on the movable valve parts would be transmitted to the hand of the operator, so as to advise him as to the extent to which the brakes are being applied by the actuator. The pedal lever need not be used, except to add further physical force to the brakes or to operate them by physical force if desired or in case of failure of power. In this case there would be no follow-up operation of the valve mechanism, and the operator, if he desired to apply the brakes gradually or to hold them as applied at an intermediate point in the stroke of the actuator, would accomplish this result by slightly relaxing his pull on the button 384.

In Fig. 4, in which the parts corresponding withthose in Fig. 2 are given the same reference numerals with the addition of 400, we have illustrated a slightly modified form of valve and a simple follow-up action by interposlng a spring i190 between the valve stem 420 and the Bowden wire, or other operative connection, to a physically operable part. In this form of the valve mechanism the diaphragm 308 is provided with a central aperture M9 within the annular seat engaging portion Mill communicating with the connection fill which in this instance leads to the closed end of a pressure balanced power actuator, while the connection 415 leads to suction. The valve is otherwise constructed in substantially the same manner as shown in Fig. 2. In this instance the Bowden wire 484 is connected to a separate casing I containing the spring 190 which is interposed between the inner end of the casing MI and the collar Mil on the valve stem. In the position of the parts illustrated in Fig. 4, the atmosphere will be connected with the cylinder in the released position of the valve mechanism, and a power stroke of the actuator can be inaugurated by pulling the casing 49l away from the valve mechanism sufficiently to compress the spring 490 to a greater or less extent and at the same time seat the disc valve MI) and unseat the diaphragm valve 408 so as to connect the actuator cylinder with suction. In this form of the invention, as the differential of fluid pressures builds up on the movable valve parts, the reactionary efiect will be exerted through the collar 420 on the spring 490 and as soon as it becomes great enough to overcome the tension of the spring as adjusted and increased by the pulling out of the casing 48 l the diaphragm will seat itself on the seat member MI shutting oil the connection between the actuator cylinder and a, reasoa suction and holding the brakes as applied. the spring casing 49! is further drawn out to further compress the spring 490, the diaphragm will again unseat and the brakes will be applied with increased force by the actuator. llhe spring 680 therefore provides a follow-up" operation in connection with the gradually increasing differential of fluid pressures on the movable valve parts, and this reactionary force is enabled to perform the two functions of apprising the operator of the extent to which the power actuator is applying force to the brakes, and also to automatically arrest the stroke of the actuator at any intermediate point and thus permit the brakes to be gradually applied.

It will be understood that the operation of the valve mechanism will be effected by causing a relative movement between the movable valve parts and the valve casing and it is immaterial how this relative movement is effected. In Figs. 1 and 5 for example, we have shown the valve casing stationarily supported by and directly connected with the intake manifold, but we wish it to be understood that the valve casing may be mounted upon any other stationary part, or it may be mounted upon a movable part and operated from a relatively movable part connected with the movable valve parts.

For example in Fig. '7, in which the parts corresponding with those shown in Fig. 1 are given the same numerals with the addition of 500, we have shown the valve mechanism of the form 11- lustrated in Fig. 2 supported by and connected with the closed end of the cylinder 5M 01 the power actuator, the connection 5 being connected by a suction pipe 5M with the intake manifold, and at least a portion of said pipe will of necessity be made flexible to accommodate the movements of the cylinder. The movable valve parts are in this instance connected with the pedal lever by the Bowden wire 584 and Bowden housing 585 connected with the bracket 582, of lever 5Bl, and with bracket 585 fastened to the valve casing, and the operation will be the same as that previously desc ibed with reference to Fig. 1.

In Figs. 8 and 9, in which the parts corresponding with those shown in Figs. 1 and 2 are given the same reference numerals with the ad dition of 600, we have shown in installation in which the valve casing is connected with and supported by the power transmitting lever Gill, while the movable valve stem is connected to an extension 688', of the pedal lever 688, the valve mechanism being operated by a pushing action instead of a pulling action and being slightly modified, as indicated in Fig. 9, to meet this situation. In this figure we have also the power actuator P4 of the vacuum balanced type in which the cylinder is closed at both ends, the forward end being connected at all times by the suction pipe 666 with the intake manifold Gil, while the rear end is connected by the pipe 655 with the connection 5 I4 of the valve casing member 606, while the connection H5 is connected with the suction pipe 666. Otherwise the valve mechanism is substantially identical with that shown in and previously described with reference to Fig. 4.

In the released position of the valve mechanism illustrated in Fig. 9, the disc valve Bill and the dlaphraghm 608 is unseated by retracting spring 589 so that both ends of the cylinder are connected with vacuum and the actuator is vacuum balanced. The depression of pedal lever 588 will first seat the diaphragm on the seat member ill to close oil communication between the rear end or the actuator cylinder and suction, after which the valve ill will be open to connect the rear end of the cylinder with atmosphere through the aperture III. In other respects the apparatus shown in Figs. 8 and 9 operates as described with reference to Figs. 1 and 2, and reaction may be provided if desired as previously described, by pivoting the power applying lever "I at 682 to a part connected with the pedal lever at a distance above the pivotal support 888' of the pedal lever.

Obviously further variations in the construction of the valve mechanism and the installation thereof may be made without departing from our invention.

What we claim and desire to secure by Letters Patent is:

1. In a brake system for automotive vehicles, the combination with brake mechanism, a power actuator operated by differential pressures having relatively movable members, a pivoted pedal lever, a power a plying lever pivotally connected therewith and operatlvely connected with brake mechanism, of means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the diiierential pressure, said valve mechanism having a valve casing provided with an annular seat, and a chamber surrounding said seat, said seat and said chamber being connected respectively with said actuator and with a source oi suction, a diaphragm provided with seat engaging means and with an air inlet valve chamber secured to and supported by the diaphragm, means for connecting said valve chamber at all times with the portion of the valve casing in communication with the actuator, an air inlet valve in said valve chamber, and connections between said valve and the pedal lever. ior operating said valve by the relative movement between it and the power applying lever.

2. In a brake system for automotive vehicles, the combination with brake mechanism, a power actuator having relatively movable members, a pivoted pedal lever, a power applying lever pivotally connected therewith and operatively connected with brake mechanism, of controlling valve mechanism comprising a valve casing provided with an annular seat, and a chamber surrounding said seat, said seat and said chamber being connected respectively with said actuator and with a source of suction, a diaphragm provided with seat engaging means and with an air inlet valve chamber secured to and supported by the diaphragm, means for connecting said valve chamber at all times with the portion of the valve casing in communication with the actuator, an air inlet valve in said valve chamber, and connections between said valve and the pedal lever, for operating said valve by the relative movement between it and the power applying lever, said power actuator being vacuum-balanced, and the diilerential oi fluid pressures on opposite faces oi the diaphragm and valve chamber, when the diaphragm is unseated reacting upon the pedal lever.

B. In a brake system for automotive vehicles, the combination with brake mechanism, a power actuator having relatively movable members, a pivoted pedal lever, a power applying lever pivotally connected therewith and operatively connected with brake mechanism, of controlling valve mechanism comprising a valve casing provided with an annular seat, and a chamber surrounding said seat, said seat and said chamber being connected respectively with said actuator and with a source of suction, a diaphragm provided with seat engaging means and with an air inlet valve chamber secured to and supported by the diaphragm, means for connecting said valve chamber at all times with the portion of the valve casing in communication with the actuator, an air inlet valve in said valve chamber. and connections between said valve and the pedal lever, for operating said valve by the relative movement between it and the power applying lever, said power actuator being vacuum-balanced, and the diilerentlal of fluid pressures on opposite faces of the diaphragm and valve chamber, when the diaphragm is unseated reacting upon the pedal lever. and the pivotal connection between the power transmitting lever and the pedal lever being so located with respect to the pivoted pedal lever as to exert reactionary force on the latter during the power stroke of the actuator.

4. In a brake system for automotive vehicles, the combination with brake mechanism, a power actuator operated by diflerential pressures having relatively movable members, a pivoted pedal lever. a power applying lever pivotally connected therewith and operatively connected with brake mechanism, of means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the differential pressure, said valve mechanism having a valve casing provided with an annular seat, and a chamber surrounding said seat, said seat and said chamber being connected respectively with said actuator and with a source of suction, a diaphragm provided with seat engaging means and with an air inlet valve chamber secured to and supported by the diaphragm. means for connecting said valve chamber at all times with the portion 0! the valve casing in communication with the actuator, an air inlet valve in said valve chamber, a Bowden wire extending from said air inlet valve to the pedal lever having one end of its casing secured rigidly with respect to the valve casing and the other secured to said power applying lever.

5. In a brake system for automotive vehicles, the combination with brake mechanism, a power actuator operated by diflerential pressure having relatively movable members, a pivoted pedal lever, a power applying lever pivotally connected therewith and operatively connected with brake mechanism, of means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the diiierential pressure, said valve mechanism having a valve casing provided with an annular seat, and a chamber surrounding said seat, said seat and said chamber being connected respectively with said actuator and with a source of suction, a diaphragm provided with seat engaging means and with an air inlet valve chamber secured to and supported by the diaphragm, means for connecting said valve chamber at all times with the portion of the valve casing in communication with the actuator, an air inlet valve in said valve chamber, and connections between said valve and the pedal leve for operating said valve by the relative movement between it and the power applying lever. and means for limiting the relative movement between the pedal lever and the power applying lever.

8. In a brake system for automotive vehicles, the combination with brake mechanism, a power actuator having relatively movable members, a pivoted pedal lever, a power applying lever pivotaily connected therewith and operatively con- 7 till Til

chamber at all times with the portion of the alve casing in communication with the actuator, an air inlet valve in said valve chamber, and connections between said valve and the pedal lever, for operating said valve by the relative movement between it and the power applying lever, said power actuator being vacuum-balanced, and the diii'erential oi fluid pressures on opposite faces of the diaphragm and valve chamber, when the diaphragm is unseated, reacting upon the pedal lever, and means for lim ting the relative movement between the pedal lever and the power applying lever.

'l. In a brake system for automotive vehicles, the combination with brake mechanism, a power actuator operated by differential pressure having relatively movable members, a pivoted pedal lever, a power applying lever pivotally connected therewith and operatively connected with brake mechanism, of means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the diil'erential pressure, said valve mechanism having a valve casing provided with an annular seat, and a chamber surrounding said seat, said seat and said chamber being connected respectively with said actuator and with a source of suction, a diaphragm provided with seat engaging means and with an air inlet valve chamber secured to and supported by the diaphragm, means for connecting said valve chamber at all times with the por tion 01' the valve casing in communication with the actuator, an air inlet valve in said valve chamber. a Bowden wire extending from said air inlet valve to the pedal lever having one end of its casing secured rigidly with respect to the valve casing and the other secured to said power applying lever, and means for limiting the relative movement between the pedal lever ant the power applying lever.

B. In a brake system for automotive vehicles provided with a throttle controlled suction passage, the combination with brake mechanism and a vacuum operated power actuator operated by diilerential pressure connected therewith, of

' means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the differential pressure, said valve mechanism having a casing having a tubular connection connected with the said suction passage and supporting said valve mechanism therefrom, and having a second tubular connection connected with the actuator, one of said connections communicating with a valve seat in said valve casing, a diaphragm having marginal portions in sealing engagement with the casing and provided with an inlet valve chamber having an air inlet aperture, said diaphragm and valve chamber being provided with valve means to engage said seat, and means for connecting said valve chamber at all times with one of said tubular connections, an air inlet valve in said valve chamber, and a physically operable part connected with said valve.

9. In a brake system for automotive vehicles provided with a throttle controlled suction passage, the combination with brake mechanism and a vacuum operated power actuator operated by dlilerential pressure connected therewith, 0! means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the diil'erential pressure, said valve mechanism having a casing having a tubular connection connected with the said suction passage and supporting said valve mechanism therefrom, and having a second tubular connection connected with the actuator, one of said connections communicating with a valve seat in said valve casing, a diaphragm having marginal portions in sealing engagement with the casing and provided with an inlet valve chamber having an air inlet aperture, said diaphragm and valve chamber being provided with valve means to engage said seat, and means for connecting said valve chamber at all times with one of said tubular connections, an air inlet valve in said valve chamber, a physically operable part, a Bowden wire connecting it with said valve, and having its casing rigidly secured adjacent to the valve casing and adjacent to said physically operable Part.

10. In a brake system for automotive vehicles provided with a throttle controlled suction passage, the combination with brake mechanism and a vacuum operated power actuator operated by diil'erential pressure connected therewith, of means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the diflerential pressure, said valve mechanism having a casing having a tubular connection connected with the said suction passage and supporting said valve mechanism therefrom, and having a second tubular connection connected with the actuator, one oi said connections communicating with a valve seat in said valve casing, a diaphragm having marginal portions in sealing engagement with the casing and provided with an inlet valve chamber having an air inlet aperture, said diaphragm and valve chamber being provided with valve means to engage said seat, and means for connecting said valve chamber at all times with one 01' said tubular connections, an air inlet valve in said valve chamber, a pivoted pedal lever, a power transmitting lever pivoted thereto and forming part of the connections between the actuator and brake mechanism, a Bowden wire connecting said air inlet valve with the pedal lever, and having its casing secured to a part in fixed relation to the valve casing and to said power transmitting lever.

11. In a brake system for automotive vehicles provided with a throttle controlled suction passage, the combination with brake mechanism and a vacuum operated power actuator operated by diilerential pressure connected therewith, of means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the difl'erential pressure, said valve mechanism having a casing having a tubular connection connected with the said suction passage and supporting said valve mechanism therefrom, and having a mound tubular connection connected with the actuator, one of said connections communicating with a valve seat in said valve casing, a diaphragm having marginal portions in sealing engagement with the casing and provided with an inlet valve chamber having an air inlet aperture, said diaphragm and valve chamber being provided withvalve means to engage said seat, and means for connecting said valve chamber at all times with one of said tubular connections, an

air inlet valve in said valve chamber, a pivoted pedal lever, a power transmitting lever pivoted thereto and forming part of the connections between the actuator and brake mechanism, a Bowden wire connecting said air inlet valve with the pedal lever, and having its casing secured to a part in flxed relation to the valve casing and to said power transmitting lever, and means for limiting the relative movement between the pedal lever and power transmitting lever.

12. In a brake system for automotive vehicles, the combination with brake mechanism, a power actuator having relatively movable members, a pivoted pedal lever, a power applying lever pivotally mounted on said pedal lever and operatively connected with the brake mechanism, of controlling valve mechanism for said power actuator comprising relatively movable parts operatively connected to said aforementioned levers, the connections being such as to transmit from the valve parts to the pedal lever a reactionary load which is a function of the degree of power loading 01' the brakes by the power actuator to thus apprise the operator of the degree of power braking.

13. A brake system for automotive vehicles comprising a brake mechanism, a power actuator having relatively movable members, a pivoted pedal lever, a power applying lever pivotally mounted on said pedal lever and operativeiy connected with the brake mechanism, the connection between said levers and the connection between the power lever and actuator being such as to provide a reactionary load upon the pedal lever as the brake is applied, and controlling valve mechanism for said power actuator comprising relatively movable parts operatively connected to said aforementioned levers, the connections being such as to transmit from the valve parts to the pedal lever a reactionary load which is a function of the degree of power loading of the brakes by the power actuator to thus apprise the operator of the degree of power braking.

14. A brake system for a motor vehicle comprising a brake, a brake applying mechanism therefor, a pedal, a fluid pressure power device for actuating said brake applying mechanism, a valve ior controlling said power device comprising a valve casing secured to a stationary part 01 said vehicle and a movable diaphragm having opposite faces subjected to diii'erential pressures corresponding to the pressures acting on said power device, a floating lever, a connection between an intermediate portion 01' said lever and said brake applying mechanism, a compression connection between one end of said lever and a part of said valve, and a pivotal connection between said pedal and said floating lever at a point on the opposite side of said applying mechanism connection from said compression connection.

15. A brake system for a motor vehicle comprising a brake, a brake applying mechanism therefor, a pedal, a fluid pressure power device for actuating said brake applying mechanism, a

valve for controlling said power device compris pedal and said floating lever at a point on the opposite side of said applying mechanism connection from said compression connection.

16. In a brake mechanism for automotive vehicles, the combination with brake mechanism, a power actuator operated by diiierential pressure having relatively movable members, a pivoted pedal lever, and a power applying lever pivotally connected therewith and operatively connected with brake mechanism, 01 means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the diil'erential pressure, and connections between said valve and the pedal lever and between the valve and the power applying lever for operating said valve by the relative movement between the pedal lever and the power applying lever.

17. In a brake mechanism for automotive vehicles, the combination with brake mechanism, a power actuator operated by differential pressure having relatively movable members, a pivoted pedal lever, and a power applying lever pivotally connected therewith and operatively connected with brake mechanism, of means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the differential pressure, an air inlet valve in said valve mechanism, a Bowden wire extending from said air inlet valve to the pivoted lever having one end of its casing secured rigidly with respect to the valve casing and the other secured to said power applying lever.

18. In a brake mechanism for automotive vehicles, the combination with brake mechanism, a power actuator operated by diii'erential pressure having relatively movable members, a pivoted pedal lever, and a power applying lever pivotally connected therewith and operatively connected with brake mechanism, of means comprising a controlling valve mechanism i'or exerting a reactionary force on the pedal proportionate to the diflerential pressure, connections between said valve and the pedal lever for operating said valve by the relative movement between it and the power applying lever, and means for limiting the relative movement between the pedal lever and the power applying lever.

19. In a braking system for automotive vehicles, the combination with brake mechanism, a power actuator operated by differential pressure, having relatively movable members, a pivoted pedal lever, and a power applying lever pivotally connected thereto and operatively connected with brake mechanism, of means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the differential pressure, an air inlet valve in said valve chamber, a Bowden wire extending from said air inlet valve to the pedal lever, having one end oi its casing secured rigidly with respect to valve casing and the other secured to said pow applying lever, and means for limiting the relative movement between the pedal lever and the power applying lever.

20. In a brake system for automotive vehicles provided with a throttle controlled suction passage, the combination with brake mechanism and a vacuum operated power actuator, operated by diflerential pressure, connected therewith, of means comprising a controlling valve mechanism for exerting a reactionary force on the pedal proportionate to the diii'erential pressure, an air inlet valve in said valve chamber, a pivoted pedal lever, a power transmitting lever pivoted thereto and forming part oi the connections betweenthsaotuatorandthebrakemechanism. ll

let valve in said valve chamber, a pivoted pedal lever, a power transmitting lever pivoted thereto and forming part of the connections between the actuator and the brake mechanism, a Bowden wire connecting said air inlet valve with the pedal lever, and having its casing secured to a part in fixed relation to the valve casing and to said power transmitting lever, and means for limiting the relative movement between -the pedal lever and the power transmitting lever.

CALEB S. BRAGG. VICTOR. W. m-IESRATH.

CERTIFICATE OF CORRECTION. Patent No. 2,15l ,,502. October 25, 95B.

CALEB S BRAGG It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, sec 0nd column, line 5, after "part." insert the following It is clear that this reactionary force is dependent upon the hydraulic pressures in the cylinder 78 inasmuch as the lever 81 actuated by the cylinder 1 must meet the resistance offered to movement of the piston 79 in order to provideareaction at 82. This reaction at 82 which is transmitted to the pedal 88 is proportionate to the resistance encountered by the piston 79 and provides a hydraulic feel on the pedal proportionate to the power supply.;

line 8, "mechanism" read mechanisms; and that the said Letters Pat nt should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 19th day of December, A. D. 1939.

Henry Van Arsdale Acting Commissioner of Patents.

let valve in said valve chamber, a pivoted pedal lever, a power transmitting lever pivoted thereto and forming part of the connections between the actuator and the brake mechanism, a Bowden wire connecting said air inlet valve with the pedal lever, and having its casing secured to a part in fixed relation to the valve casing and to said power transmitting lever, and means for limiting the relative movement between -the pedal lever and the power transmitting lever.

CALEB S. BRAGG. VICTOR. W. m-IESRATH.

CERTIFICATE OF CORRECTION. Patent No. 2,15l ,,502. October 25, 95B.

CALEB S BRAGG It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, sec 0nd column, line 5, after "part." insert the following It is clear that this reactionary force is dependent upon the hydraulic pressures in the cylinder 78 inasmuch as the lever 81 actuated by the cylinder 1 must meet the resistance offered to movement of the piston 79 in order to provideareaction at 82. This reaction at 82 which is transmitted to the pedal 88 is proportionate to the resistance encountered by the piston 79 and provides a hydraulic feel on the pedal proportionate to the power supply.;

line 8, "mechanism" read mechanisms; and that the said Letters Pat nt should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 19th day of December, A. D. 1939.

Henry Van Arsdale Acting Commissioner of Patents. 

